How representative are 1000 Genomes samples?

Top Pseudo Science/

1000 Genomes made an effort to collect representative samples of several (as of today, 26) ethnic groups. A typical condition is that 3 or 4 of the grandparents share the same ancestral origin or come from the same geographical region as the participant. However, an emphasis on genetic/ancestral “purity” has been achieved by focusing on rural areas in some instances, which may or may not be representative of the entire population, particularly for some traits. It has been shown by several studies that city dwellers have an intellectual advantage over rural folks, in terms of IQ. Moreover, city dwellers also tend to be better educated. This would introduce bias when 1000 Genomes samples are used to compare populations on frequencies of alleles related to educational attainment or intelligence.

Unfortunately, detailed sample information for 1000 Genomes is (to the best of my knowledge) not reported on the 1000 Genomes website and I found it through the Wikipedia link to the Corriell Institute for Medical research. This is a body whose existence I ignored, but day after day I realize that population genetics information is scattered all over the web and not as well organized as I used to believe.